highCVE-2025-53379

CVE-2025-53379 in Fortinet FortiAuthenticator

A out-of-bounds read vulnerability in Fortinet FortiAuthenticator 6.6.0 through 6.6.2, FortiAuthenticator 6.5 all versions may allow a remote unauthenticated attacker to retrieve sensitive information via a specially crafted request.

ProductFortiAuthenticator
CVSS7.5
EPSSNot scored yet
UpdatedJuly 16, 2026

Quick answer

Fortinet FortiAuthenticator should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.

Who is affected

Affected versions

  • FortiAuthenticator 6.5.x
  • FortiAuthenticator 6.6.0 through 6.6.2

Fixed versions

  • FortiAuthenticator 6.5.8 or later
  • FortiAuthenticator 6.6.3 or later

How to fix it

CVE-2025-53379 is a information disclosure issue in FortiAuthenticator. Update from FortiAuthenticator 6.5.x to FortiAuthenticator 6.5.8 or later or newer. Keep it simple: upgrade first, then test the normal user flow.

  1. Find every place where FortiAuthenticator is installed or used.
  2. Upgrade FortiAuthenticator to FortiAuthenticator 6.5.8 or later or a newer fixed release from the vendor.
  3. If you cannot upgrade right away, limit access to the affected feature until the update is done.
  4. Restart or redeploy the service if the product needs it after the update.

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Verify the fix

  • Confirm the installed version is FortiAuthenticator 6.5.8 or later or newer.
  • Run a normal login, admin, and user flow to make sure the site still works.
  • Check logs for new errors after the update.

Related categories

Trusted references

FAQ

What is affected by CVE-2025-53379?

Fortinet FortiAuthenticator versions listed as affected should be reviewed: FortiAuthenticator 6.5.x, FortiAuthenticator 6.6.0 through 6.6.2.

What should I fix first?

Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.

How do I confirm the fix worked?

Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.

How are Fixnx security risk categories chosen?

Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.